Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/drivers/mfd/ti_am335x_tscadc.c

  1 /*
  2  * TI Touch Screen / ADC MFD driver
  3  *
  4  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License as
  8  * published by the Free Software Foundation version 2.
  9  *
 10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 11  * kind, whether express or implied; without even the implied warranty
 12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13  * GNU General Public License for more details.
 14  */
 15 
 16 #include <linux/module.h>
 17 #include <linux/slab.h>
 18 #include <linux/err.h>
 19 #include <linux/io.h>
 20 #include <linux/clk.h>
 21 #include <linux/regmap.h>
 22 #include <linux/mfd/core.h>
 23 #include <linux/pm_runtime.h>
 24 #include <linux/of.h>
 25 #include <linux/of_device.h>
 26 #include <linux/sched.h>
 27 
 28 #include <linux/mfd/ti_am335x_tscadc.h>
 29 
 30 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
 31 {
 32         unsigned int val;
 33 
 34         regmap_read(tsadc->regmap_tscadc, reg, &val);
 35         return val;
 36 }
 37 
 38 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
 39                                         unsigned int val)
 40 {
 41         regmap_write(tsadc->regmap_tscadc, reg, val);
 42 }
 43 
 44 static const struct regmap_config tscadc_regmap_config = {
 45         .name = "ti_tscadc",
 46         .reg_bits = 32,
 47         .reg_stride = 4,
 48         .val_bits = 32,
 49 };
 50 
 51 void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val)
 52 {
 53         unsigned long flags;
 54 
 55         spin_lock_irqsave(&tsadc->reg_lock, flags);
 56         tsadc->reg_se_cache |= val;
 57         if (tsadc->adc_waiting)
 58                 wake_up(&tsadc->reg_se_wait);
 59         else if (!tsadc->adc_in_use)
 60                 tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
 61 
 62         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
 63 }
 64 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
 65 
 66 static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
 67 {
 68         DEFINE_WAIT(wait);
 69         u32 reg;
 70 
 71         /*
 72          * disable TSC steps so it does not run while the ADC is using it. If
 73          * write 0 while it is running (it just started or was already running)
 74          * then it completes all steps that were enabled and stops then.
 75          */
 76         tscadc_writel(tsadc, REG_SE, 0);
 77         reg = tscadc_readl(tsadc, REG_ADCFSM);
 78         if (reg & SEQ_STATUS) {
 79                 tsadc->adc_waiting = true;
 80                 prepare_to_wait(&tsadc->reg_se_wait, &wait,
 81                                 TASK_UNINTERRUPTIBLE);
 82                 spin_unlock_irq(&tsadc->reg_lock);
 83 
 84                 schedule();
 85 
 86                 spin_lock_irq(&tsadc->reg_lock);
 87                 finish_wait(&tsadc->reg_se_wait, &wait);
 88 
 89                 reg = tscadc_readl(tsadc, REG_ADCFSM);
 90                 WARN_ON(reg & SEQ_STATUS);
 91                 tsadc->adc_waiting = false;
 92         }
 93         tsadc->adc_in_use = true;
 94 }
 95 
 96 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
 97 {
 98         spin_lock_irq(&tsadc->reg_lock);
 99         tsadc->reg_se_cache |= val;
100         am335x_tscadc_need_adc(tsadc);
101 
102         tscadc_writel(tsadc, REG_SE, val);
103         spin_unlock_irq(&tsadc->reg_lock);
104 }
105 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
106 
107 void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc)
108 {
109         unsigned long flags;
110 
111         spin_lock_irqsave(&tsadc->reg_lock, flags);
112         tsadc->adc_in_use = false;
113         tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
114         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
115 }
116 EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
117 
118 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
119 {
120         unsigned long flags;
121 
122         spin_lock_irqsave(&tsadc->reg_lock, flags);
123         tsadc->reg_se_cache &= ~val;
124         tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
125         spin_unlock_irqrestore(&tsadc->reg_lock, flags);
126 }
127 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
128 
129 static void tscadc_idle_config(struct ti_tscadc_dev *config)
130 {
131         unsigned int idleconfig;
132 
133         idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
134                         STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
135 
136         tscadc_writel(config, REG_IDLECONFIG, idleconfig);
137 }
138 
139 static  int ti_tscadc_probe(struct platform_device *pdev)
140 {
141         struct ti_tscadc_dev    *tscadc;
142         struct resource         *res;
143         struct clk              *clk;
144         struct device_node      *node = pdev->dev.of_node;
145         struct mfd_cell         *cell;
146         struct property         *prop;
147         const __be32            *cur;
148         u32                     val;
149         int                     err, ctrl;
150         int                     clock_rate;
151         int                     tsc_wires = 0, adc_channels = 0, total_channels;
152         int                     readouts = 0;
153 
154         if (!pdev->dev.of_node) {
155                 dev_err(&pdev->dev, "Could not find valid DT data.\n");
156                 return -EINVAL;
157         }
158 
159         node = of_get_child_by_name(pdev->dev.of_node, "tsc");
160         of_property_read_u32(node, "ti,wires", &tsc_wires);
161         of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
162 
163         node = of_get_child_by_name(pdev->dev.of_node, "adc");
164         of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
165                 adc_channels++;
166                 if (val > 7) {
167                         dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
168                                         val);
169                         return -EINVAL;
170                 }
171         }
172         total_channels = tsc_wires + adc_channels;
173         if (total_channels > 8) {
174                 dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
175                 return -EINVAL;
176         }
177         if (total_channels == 0) {
178                 dev_err(&pdev->dev, "Need atleast one channel.\n");
179                 return -EINVAL;
180         }
181 
182         if (readouts * 2 + 2 + adc_channels > 16) {
183                 dev_err(&pdev->dev, "Too many step configurations requested\n");
184                 return -EINVAL;
185         }
186 
187         /* Allocate memory for device */
188         tscadc = devm_kzalloc(&pdev->dev,
189                         sizeof(struct ti_tscadc_dev), GFP_KERNEL);
190         if (!tscadc) {
191                 dev_err(&pdev->dev, "failed to allocate memory.\n");
192                 return -ENOMEM;
193         }
194         tscadc->dev = &pdev->dev;
195 
196         err = platform_get_irq(pdev, 0);
197         if (err < 0) {
198                 dev_err(&pdev->dev, "no irq ID is specified.\n");
199                 goto ret;
200         } else
201                 tscadc->irq = err;
202 
203         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
204         tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res);
205         if (IS_ERR(tscadc->tscadc_base))
206                 return PTR_ERR(tscadc->tscadc_base);
207 
208         tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
209                         tscadc->tscadc_base, &tscadc_regmap_config);
210         if (IS_ERR(tscadc->regmap_tscadc)) {
211                 dev_err(&pdev->dev, "regmap init failed\n");
212                 err = PTR_ERR(tscadc->regmap_tscadc);
213                 goto ret;
214         }
215 
216         spin_lock_init(&tscadc->reg_lock);
217         init_waitqueue_head(&tscadc->reg_se_wait);
218 
219         pm_runtime_enable(&pdev->dev);
220         pm_runtime_get_sync(&pdev->dev);
221 
222         /*
223          * The TSC_ADC_Subsystem has 2 clock domains
224          * OCP_CLK and ADC_CLK.
225          * The ADC clock is expected to run at target of 3MHz,
226          * and expected to capture 12-bit data at a rate of 200 KSPS.
227          * The TSC_ADC_SS controller design assumes the OCP clock is
228          * at least 6x faster than the ADC clock.
229          */
230         clk = clk_get(&pdev->dev, "adc_tsc_fck");
231         if (IS_ERR(clk)) {
232                 dev_err(&pdev->dev, "failed to get TSC fck\n");
233                 err = PTR_ERR(clk);
234                 goto err_disable_clk;
235         }
236         clock_rate = clk_get_rate(clk);
237         clk_put(clk);
238         tscadc->clk_div = clock_rate / ADC_CLK;
239 
240         /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
241         tscadc->clk_div--;
242         tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);
243 
244         /* Set the control register bits */
245         ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
246         tscadc_writel(tscadc, REG_CTRL, ctrl);
247 
248         /* Set register bits for Idle Config Mode */
249         if (tsc_wires > 0) {
250                 tscadc->tsc_wires = tsc_wires;
251                 if (tsc_wires == 5)
252                         ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
253                 else
254                         ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
255                 tscadc_idle_config(tscadc);
256         }
257 
258         /* Enable the TSC module enable bit */
259         ctrl |= CNTRLREG_TSCSSENB;
260         tscadc_writel(tscadc, REG_CTRL, ctrl);
261 
262         tscadc->used_cells = 0;
263         tscadc->tsc_cell = -1;
264         tscadc->adc_cell = -1;
265 
266         /* TSC Cell */
267         if (tsc_wires > 0) {
268                 tscadc->tsc_cell = tscadc->used_cells;
269                 cell = &tscadc->cells[tscadc->used_cells++];
270                 cell->name = "TI-am335x-tsc";
271                 cell->of_compatible = "ti,am3359-tsc";
272                 cell->platform_data = &tscadc;
273                 cell->pdata_size = sizeof(tscadc);
274         }
275 
276         /* ADC Cell */
277         if (adc_channels > 0) {
278                 tscadc->adc_cell = tscadc->used_cells;
279                 cell = &tscadc->cells[tscadc->used_cells++];
280                 cell->name = "TI-am335x-adc";
281                 cell->of_compatible = "ti,am3359-adc";
282                 cell->platform_data = &tscadc;
283                 cell->pdata_size = sizeof(tscadc);
284         }
285 
286         err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
287                         tscadc->used_cells, NULL, 0, NULL);
288         if (err < 0)
289                 goto err_disable_clk;
290 
291         device_init_wakeup(&pdev->dev, true);
292         platform_set_drvdata(pdev, tscadc);
293         return 0;
294 
295 err_disable_clk:
296         pm_runtime_put_sync(&pdev->dev);
297         pm_runtime_disable(&pdev->dev);
298 ret:
299         return err;
300 }
301 
302 static int ti_tscadc_remove(struct platform_device *pdev)
303 {
304         struct ti_tscadc_dev    *tscadc = platform_get_drvdata(pdev);
305 
306         tscadc_writel(tscadc, REG_SE, 0x00);
307 
308         pm_runtime_put_sync(&pdev->dev);
309         pm_runtime_disable(&pdev->dev);
310 
311         mfd_remove_devices(tscadc->dev);
312 
313         return 0;
314 }
315 
316 #ifdef CONFIG_PM
317 static int tscadc_suspend(struct device *dev)
318 {
319         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
320 
321         tscadc_writel(tscadc_dev, REG_SE, 0x00);
322         pm_runtime_put_sync(dev);
323 
324         return 0;
325 }
326 
327 static int tscadc_resume(struct device *dev)
328 {
329         struct ti_tscadc_dev    *tscadc_dev = dev_get_drvdata(dev);
330         u32 ctrl;
331 
332         pm_runtime_get_sync(dev);
333 
334         /* context restore */
335         ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
336         tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
337 
338         if (tscadc_dev->tsc_cell != -1) {
339                 if (tscadc_dev->tsc_wires == 5)
340                         ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
341                 else
342                         ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
343                 tscadc_idle_config(tscadc_dev);
344         }
345         ctrl |= CNTRLREG_TSCSSENB;
346         tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
347 
348         tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
349 
350         return 0;
351 }
352 
353 static const struct dev_pm_ops tscadc_pm_ops = {
354         .suspend = tscadc_suspend,
355         .resume = tscadc_resume,
356 };
357 #define TSCADC_PM_OPS (&tscadc_pm_ops)
358 #else
359 #define TSCADC_PM_OPS NULL
360 #endif
361 
362 static const struct of_device_id ti_tscadc_dt_ids[] = {
363         { .compatible = "ti,am3359-tscadc", },
364         { }
365 };
366 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
367 
368 static struct platform_driver ti_tscadc_driver = {
369         .driver = {
370                 .name   = "ti_am3359-tscadc",
371                 .owner  = THIS_MODULE,
372                 .pm     = TSCADC_PM_OPS,
373                 .of_match_table = ti_tscadc_dt_ids,
374         },
375         .probe  = ti_tscadc_probe,
376         .remove = ti_tscadc_remove,
377 
378 };
379 
380 module_platform_driver(ti_tscadc_driver);
381 
382 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
383 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
384 MODULE_LICENSE("GPL");
385 

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